Dropped Third Strike - Interference

[tcblue13]

The other thread on a D2K reminded of a situation that I had last week.

Private Schools using Fed rules
Bases loaded, 1 out

Catcher drops third strike and the dugout (actually the girls in the offensive dugout) start yelling RUN RUN. The Batter takes off and the panicked catcher heaves a bad throw to first and two runs score. I was BU and was unsure about calling interference. The PU correctly declared the batter out on strikes since 1B was occupied but let the results of the play stand. I asked him about the interference and he said not to worry about it. By that time, it was over anyway. I am trying to just be aware for future reference.

1. Would interference have been the correct call?
2. Would the runner on 3B also be out on the interference call?